It is true - Iguanas DO sneeze. In fact, they will probably do it quite often. Since Iguanas do not sweat like humans do, they excrete salt by sneezing. That would be why there is white spots on the glass sides of the cage (if you use glass for the sides). It will clean up very easily, so don’t worry about it. Whether it sneezes a lot or not often at all, though, don’t get too worked up about your Iguana’s sneezing habits, and don’t try to alter it’s diet to change the amount of excretion.

You should, however, be paying attention to the Iguana’s breathing. They can pick up respiratory infections, and there are a couple signs you should notice if it happens:

1. Loud breathing. You normally do not hear the Iguana breathing. If you do, check it out.

2. Bubbles or liquid outside of the nose and mouth. This can also indicate a respiratory infection.

 * If you ever notice your Ig’s behavior indicating signs of a sickness, call the veterinarian and increase the cage temperature.

 
2. Head Bobbing.

Yes, this is a normal behavior for an Iguana - especially a male Iguana. This display of behavior is not resulting from your playing of Queen’s "Bohemian Rhapsody", though. There are many reasons an Iguana will bob it’s head, and it usually will begin after the first year of it’s life.

If there are other Iguanas in the cage or room, it may be a territorial display or mating ritual. But if there are no other Iguanas around, it may be bobbing it’s head at you - trying to give you a signal, maybe to get away or leave it alone. Iguanas sometimes will bob their heads at a reflection of themselves in a mirror where the reflection of themselves is upsetting them. That is why some Iguanas should be kept away from mirrors. Others are not bothered by their reflection at all, and may even like to see themselves. It depends on your experiences with your pet.

When there is more than one Iguana in a confined space, be aware of their behavior toward one another. As I described in the section Housing: Multiple Iguanas, having more than one Iguana in the same cage or room may cause problems. Especially males, Iguanas are very territorial, and a display of head bobbing may a warning to the other to "get off my branch" or "out of my way". During mating season, it may be a warning to the same sex to "get away from my mate". If it is a male bobbing to a female, it is usually a message that the male is interested in mating.

Just be aware of the head-bobbing. It is often a sign that the Iguanas are acting very territorial toward one another, and if this is the case, one of them is bound to get hurt. My suggestion: at first sign, separate them before anything bad happens.